The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingCanceling and resuming
the speed control
Pressing the cancel switch
cancels the speed control.
The speed control is also canceled
when the brake pedal is depressed.
(When the vehicle has been
stopped by system control,
depressing the brake pedal does
not cancel the setting.)
Pressing the "+RES" switch
resumes the cruise control
a ...
Ig power supply voltage malfunction
Description
The power steering ecu distinguishes the ignition switch status as on or off
through the ig power
source circuit.
Wiring diagram
Inspection procedure
Read value of intelligent tester (ig power supply)
Connect the intelligent tester (with can vim) to the
dlc3.
...
Removal
Remove radiator grille sub-assembly
Remove the 4 bolts and 4 nuts.
Detach the 6 claws and remove the radiator grille.
Remove no. 1 Radiator grille lower
Detach the 16 claws and remove the radiator grille.
Remove no. 2 Radiator grille lower
Detac ...